Periodic Table

Question 1

How are they classified?

Answer 1

According to the group (valence e) and period (no. of e shells)

Question 2

Why are group 1 elements stored in oil

Answer 2

Grp 1 elements are very reactive. Hence, they are stored in oil as they do not react with oil

Question 3

Grp 1 (Alkali metals)

Answer 3

-Very reactive (increases down the grp)

-Low mp/bp (decreases down the grp)

-Soft (can cut with knife)

-Low density (increases down the grp)

-High reducing power (increases down the grp)

Question 4

Grp 7 (Halogens)

Answer 4

-Diatomic molecules

-Coloured molecules (Colour intensity increases down the grp)

-Mp/bp increases down the grp

-Reactivity decreases down the grp

-Oxidising power decreases down the grp

-Do not conduct electricity

Question 5

Colour of F2 (g)

Answer 5

Light green

Question 6

Colour of Cl2 (g)

Answer 6

Yellow-green

Question 7

Colour of Br2 (l)

Answer 7

Reddish-brown

Question 8

Colour of I2 (s)

Answer 8

Blue-black

Question 9

Colour of As2 (s)

Answer 9

Black

Question 10

Colour of CuO (s)

Answer 10

Black

Question 11

Colour of I2 (aq)

Answer 11

Brown

Question 12

Colour of I2(g)

Answer 12

Purple

Question 13

Colour of pure copper (s)

Answer 13

Pink

Question 14

Colour of CuCO3

Answer 14

Green

Question 15

Colour of CuCl2

Answer 15

Greenish-blue

Question 16

Noble gases (Grp 0)

Answer 16

-Stable configuration

-Unreactive

-Monoatomic gas

Question 17

Uses of noble gases: Helium

Answer 17

Hot air balloon

Question 18

Uses of noble gases: Neon

Answer 18

Signboards

Question 19

Uses of noble gases: Argon

Answer 19

Inert atmosphere for welding (does not react with surroundings)

Question 20

Transition metals

Answer 20

-Variable oxidation states (catalysts)

-Tend to form coloured ions

-High mp/bp (metals)

-Electrical conductors (metals)

-Malleable and ductile (metals)

Question 21

Displacement reactions

Answer 21

More reactive halogen replaces less reactive halogen